Simulation of the Commerson eruption

The Commerson Crater is a large volcanic crater on the Reunion Island. Over 200 meters large and 120 meters deep. It was formed approximately 1850 years ago during a phreatomagmatic eruption. The simulator was used to show the main phases of the eruption.

Video 1 - Back in time

This first video show the transition between the present aerial view of the Commerson crater, and the view at the same place about 1850 years ago at the beginning of the eruption, before the valley was filled in with lava flow.

At the beginning of the eruption, the « Rivière des Remparts » valley appears as it was before the valley was filled in by the lava flow.

The first phase of the eruption is intense but not explosive. The magma, rich in gaz, comes from deep origine.



Video 2 - Commerson cone

The projections formed a large cone at the place of the actual crater.

It appears that in the first phase of the eruption the crack remains opened at the top of the cliff, and formed a volcanic cone. The video shows an aerial view of the cone created by the simulation.



Video 3 - Draining in valley

This video shows the next phase of the eruption. The pressure is too high and the lava suddenly flows out into the valley.

The magma break through the rock between the chimney and the valley, a large lava flow then comes out below from the third crater.

The lava level drops rapidly in the first two craters, then the groundwater is aspirated by the depression and a violent phreatomagmatic explosion occur.



Video 4 - Lava lake after explosion

After the explosion, the pressure maintains a lava lake in the crater, while the lava continue to flow into the valley.

The explosion completely destroyed the previously formed cone.. and created an explosion crater. Then the calm returns and a lava lake is formed inside the new crater.
The projections do not reach the crater rim.



Video 5 - Lava flows along the valley

The eruption is about to finish, the lava reach the ocean.

The lava follows the valley and reach the coast, about 20 km farther. The total volume of lava is estimated at 200-300 millions of m³ ! Far more than historic eruptions.



Other images

Another images rendered in the simulator from different points of view.






Copyright © 2015 E.Chahi & F.Sahy